MILFORD -- Neighbors cheerily admiring the growth of others' children and applauding college-bound teens outside the Jonathan Law High School football field Monday night went suddenly silent as a somber group, ringed by police officers, glided through their midst toward the field.

It was the family of slain student Maren Sanchez. And just like that, the mood suddenly changed and quietly, and with reverence, people filed into the field behind the family.

"We are here to celebrate the life of a wonderful student," began Principal Fran Thompson, as a slight breeze flickered the flames on hundreds of candles mounted on the bleachers behind her. "We are like a family, and our heart is broken."

Many in the crowd murmured it was a testament to the girl that about 2,000 people had come out to pay tribute to her.

"We will never be able to measure your loss, never be able to undo what was done," Mayor Ben Blake told them. "We can only promise to keep Maren's spirit in our hearts.

The 16-year-old Sanchez, an athlete and National Honor Society member, was confronted by longtime friend Christopher Plaskon, 16, in a first-floor hallway shortly after 7 a.m. before classes began Friday. Police said Sanchez was slashed across the throat, face and chest. They said at least a portion of the attack was witnessed, and a teacher's aide held the dying girl's head in her lap until help arrived. She was pronounced dead at Bridgeport Hospital.

Plaskon was arrested a short time later and was cooperative, police said. They said the knife he used was left at the scene.

Sanchez's friends and classmates said Plaskon killed Sanchez after she refused to go with him to the junior prom, which was to be held that evening.

Plaskon, who is expected to be charged with murder, has been undergoing a psychiatric evaluation and did not appear in juvenile court in New Haven -- the first step in his prosecution -- on Monday. His lawyers, Richard Meehan and Edward Gavin of Bridgeport, declined comment on the case Monday.

Gov. Dannel P. Malloy looked out at the crowd on the football field and in the bleachers Monday night and pondered Sanchez's loss to the community.

"There are more than a few of us who are jealous of the power she had over others," he said.

Superintendent of Schools Elizabeth Feser said she was wracked with guilt.

"Each and every child in the Milford public schools are precious to me," she said. "I am filled with grief, the loss of Maren, one of our own. I grieve also the loss of innocence for so many of our students, and it is not right."

But if there had been a spotlight that evening it would have been on four sobbing teenagers -- Sanchez's boyfriend and intended prom date, Jarrod Butts and her three best friends, Giovanni Marzullo, Evelyn Castro and Phoebe Herbert -- who, leaning on each other for support, stood to speak.

Butts had known Sanchez since the fourth grade.

"She never had a problem with anyone," he said, his voice cracking with emotion. "One of my favorite memories is being on the beach with her in the eighth grade ... we all love you so much and we greatly miss you."